HAYABUSA2@JAXAVarmennettu tili

[TD1 - L08E1] We began the spacecraft descent operation today (2/21) at 06:30 JST. At the moment, we are still in the judgment phase of deciding whether to begin descent and the spacecraft remains at the home position at an altitude of 20km. The spacecraft’s condition is normal.

[TD1 - L08E1] Today (2/21) 12: 36 (JST), the decision to begin the touchdown operation was declared as "GO". While the descent start time is delayed about 5 hours, the speed to 5km altitude will be increased slightly so there is no change to the scheduled time for touchdown.

[TD1-L08E1] On February 21 at 13:45 JST, the Doppler data confirms that the spacecraft had started to descend. The descent speed was about 90 cm/s. This is swifter than the scheduled 40 cm/s, as the delay in the descent start time meant we increased the descent speed.

[TD1-L08E1] On February 21 at 16:00 JST, the altitude of the spacecraft (distance from Ryugu) was about 12 km. The altitude is decreasing smoothly.

[TD1-L08E1] Today’s ground station operations was from the US Goldstone station until dawn, then to Usuda station and after that it moved across to Canberra and now operation is from Madrid. Check out Haya2NOW to see who we’re talking through! http://haya2now.jp/ 

[TD1-L08E1] February 21 at 17:00 JST: the altitude of the spacecraft has passed 9 km. This is the time confirmed in the control room. It takes about 19 minutes for the radio waves to be transmitted from Hayabusa2, so this will be from 19 minutes ago.

[TD1-L08E1] At a spacecraft altitude of 6500m (around 2/21 at 17:30 JST), the speed of the spacecraft was slowed to about 40 cm/s. This is the initial descent speed and means we are now back to our original descent plan.